本論文利用數值模擬的方法來分析, 與大氣環境相連之單一房間及兩個房間內的置換式通風研究。在單一房間之分析問題中, 分別改變不同的開口有效面積、房間高度及熱源強度來觀察流場之改變型態。兩個房間之分析問題則是將單一房間之分析問題加以延伸探討, 將單一房間具有低開口處的邊上連接上一個無熱源的房間, 分別改變無熱源房間之大小、開口設置高度及熱源強度來觀察流場之改變型態。本文採有限體積法配合k-ε 紊流模式求解質量守衡、動量守恆及能量守恆方程式來模擬流場之流動情形及溫度分佈。
由單一房間之模擬結果得知, 當流場達穩態時室內的溫度會隨高度而有漸層的分佈情形,且介面層高度僅與開口有效面積及房間的高度有關與熱源之強度無關, 驗證了實驗及理論公式之延究結果。
由兩個房間之模擬結果可知, 改變無熱源房間之大小及開口設置高度皆能有效達成置換式通風之機制。當流場達到穩態時無熱源房間內的溫度皆與外在環境相同不會受到有熱源間之影響, 有熱源房間內的溫度會隨著高度而有漸層的分佈情形。且介面層高度亦不會隨著熱源強度的不同而有所改變。

Numerical studies on displacement ventilation in a single room and two connected rooms are presented. In the analysis of single room, we use various effective area, height of room and magnitudes of heating power to observe variation of the flow field. Displacement ventilation in two connected rooms is a further study. In two connected rooms case a heat source is only placed in one room, referred as a forced room, and the other room, unforced room, has no heat source. The analysis of two connected rooms is extending the single room case, an unforced room is connected to one side of forced room at a bottom opening. In order to observe variation of the flow field, in those two rooms we change the room size, opening position and heating power in the unforced room. The finite volume method and standard k-ε
turbulence model are employed to describe structures and characteristics of flows.
According to the simulation results of displacement ventilation in a single room, when the flow field reaches the steady state, the temperature distribution is stratified with height. The height of interface is independent of the heating power and depends only on the height of rooms and effective area. The results agree with the experiment and theoretical analysis of previous research.
In terms of the simulation results of displacement ventilation in two connected
rooms, changing the size and opening position of the unforced room can gener-
ates displacement ventilation. When the flow field reaches the steady state, the isothermal distribution in the unforced room would be the same as ambient environment. The temperature in the forced room would be stratified with respect to height. The height of interface is also independent of the heating power in two rooms.

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